<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div {
      display: inline-block;
      width: 300px;
      height: 300px;
    }

    .box {
      /* width */
      /* border-top-width: 10px;
      border-right-width: 20px;
      border-bottom-width: 30px;
      border-left-width: 40px; */

      border-width: 10px 20px 30px 40px;
      /* style */
      /* border-top-style: solid;
      border-right-style: dashed;
      border-bottom-style: groove;
      border-left-style: ridge; */

      border-style: solid dashed groove ridge;
      /* color */
      /* border-top-color: red;
      border-right-color: blue;
      border-bottom-color: green;
      border-left-color: orange; */

      border-color: red blue green orange;
    }

    .box1 {
      border: 10px solid red;
    }

    .box2 {
      border: 10px solid;
    }
  </style>
</head>

<body>
  <div class="box">我是box</div>
  <hr>
  <div class="box1">我是box1</div>
  <hr>
  <div class="box2">我是box2</div>
</body>

</html>